The present invention relates generally to a water purification apparatus and, more particularly, to a portable water purifying and germicidal disinfecting system that utilizes ultraviolet radiation to prepare water for human consumption.
Natural water supplies can be contaminated by any number of disease-carrying microorganisms from bacteria to protozoa to viruses. Consuming water that contains these organisms can lead to cramps, vomiting, diarrhea and even more serious medical problems. For water to be safe to drink, these microorganisms must be either rendered inactive or removed.
There exists a need for portable water treatment systems for providing water suitable for human consumption at remote locations. This need exists, for example, in rural areas where sophisticated water treatment facilities are not present, and in the aftermath of disasters such as earthquakes and hurricanes where the local water supply has been contaminated or disrupted. While enjoying recreational activities of extended periods of time, such as hiking or camping, there is a need for water to be purified in relatively small quantities. In these instances, some effective method of treating local water supplies becomes necessary.
Various devices have been developed to disinfect water using irradiation of infected water with certain frequencies of electromagnetic radiation such as those in the ultra-violet range. U.S. Pat. No. 4,849,100 issued to Papandrea discloses a portable water purifier which shuts off the water flow therethrough upon sensing that the ultraviolet light intensity has fallen below a predetermined level, in an attempt to ensure that all of the water is sufficiently purified. U.S. Pat. No. 4,755,292 issued to Merriam discloses a portable ultraviolet water sterilizer with ultraviolet reflective sidewalls, in an attempt to shield the user from harmful ultraviolet radiation and cause the water to be efficiently exposed to ultraviolet light.
The devices used heretofore have generally proved to be unsatisfactory for one or more reasons. Most irradiation water purification devices have been designed to remain stationary, having the water flow through as it is exposed to ultraviolet light, and thus require the use of a pump. Certain apparatuses of this type become coated with materials opaque to ultraviolet light after repeated use, and thus prevents satisfactory disinfection. Other devices do not provide a sufficient duration or intensity of ultraviolet light to fully disinfect the water. Many of the portable devices fail to provide a sufficient amount of ultraviolet light, as to do so might cause the ultraviolet bulb to overheat and become inoperable. Other devices have relied on the tendency of ultraviolet light to catalyze the formation of ozone from oxygen. However, these devices require a great deal of power to be consumed, and if portable, a bulky power source to be attached.
A portable water system must be compact, lightweight, and convenient to use. In addition to these requirements, a portable water purification system must be effective in purifying water to a suitable quality. It is also desirable that such a system not require the addition of chemicals and the like to be added to the water which either may lessen the quality of the treated water or require additional supplies.
High levels and prolonged exposure to ultraviolet light has been shown in recent years to cause various skin cancers, defects relating to human eyes, and the breakdown of human deoxyribonucleic acid. Therefore, it is desirable for the ultraviolet radiation utilized by the device to be prevented from escaping the device and effecting those who wish to benefit from the device""s water purification.
A number of portable ultraviolet water purification devices have attempted to fulfill this need. U.S. Pat. No. 4,849,100 issued to Papandrea discloses a portable water purifier which shuts off the water flow therethrough upon sensing that the ultraviolet light intensity has fallen below a predetermined level, in an attempt to ensure that all of the water is sufficiently purified. U.S. Pat. No. 4,755,292 issued to Merriam discloses a portable ultraviolet water sterilizer with ultraviolet reflective sidewalls, in an attempt to shield the user from harmful ultraviolet radiation and cause the water to be efficiently exposed to ultraviolet light. However, these devices fall short of providing an efficient, durable, convenient, reliable portable purification device for drinking water. For example, the Merriam device is not shaped to be carried but is more of a bucket, the light source does not secure or seal to the container, the container does not seal, and there is no provision for cooling the light source. The Papandrea device requires water to flow therethrough making it poorly suited to portable use.
These problems of past devices have been overcome by the present invention, a portable water purification system. The portable water purification system of the present invention includes a container in which water is to be placed. Attached to the container is an ultraviolet light source which irradiates the water, the inside surfaces of the top and side portions of the container are coated with an ultraviolet reflective material. The entire container is made of a material opaque to ultraviolet light. A battery is provided in order to provide power to the ultraviolet light source. Additionally, a sensor is provided in order to determine when the water being purified has received an adequate dose of ultraviolet radiation. Upon this determination the operator of the purification device is notified and the ultraviolet light source of the present invention is automatically shut off.